Comparative investigation of silicon photomultipliers as possible photon detectors for the Cherenkov Telescope Array

One of most interesting improvements in CTA observatory will be the use of silicon photomultipliers (SiPMs) as pho- ton detectors for the telescope cameras. SiPMs have many key advantages compared with photomultiplier tubes, however they have also some drawbacks, such as dark noise, cross-talk and afterpulses. Moreover several companies produce a multitude of different types of SiPMs, since they stand as a very promising technology to replace photomultiplier tube in many applications. A comparative investigation of SiPMs\u2019 properties using a semi-automated test setup is therefore a powerful instrument to identify the best device for CTA telescope cameras

Vision-Based Navigation III: Pose and Motion from Omnidirectional Optical Flow and a Digital Terrain Map

An algorithm for pose and motion estimation using corresponding features in omnidirectional images and a digital terrain map is proposed. In previous paper, such algorithm for regular camera was considered. Using a Digital Terrain (or Digital Elevation) Map (DTM/DEM) as a global reference enables recovering the absolute position and orientation of the camera. In order to do this, the DTM is used to formulate a constraint between corresponding features in two consecutive frames. In this paper, these constraints are extended to handle non-central projection, as is the case with many omnidirectional systems. The utilization of omnidirectional data is shown to improve the robustness and accuracy of the navigation algorithm. The feasibility of this algorithm is established through lab experimentation with two kinds of omnidirectional acquisition systems. The first one is polydioptric cameras while the second is catadioptric camera.Comment: 6 pages, 9 figure

Feasibility Study of Miniature LWIR Cameras in Quantitative Thermal Measurements

Thermal imaging in scientific applications has traditionally involved large and expensive cameras with static mounting. Applications of thermal imaging include: gas detection, heat sensing, stress analysis of materials, as well as many other research applications. This research studies the feasibility of replacing large thermal cameras with the FLIR Lepton, a miniature thermal sensor with a resolution of 60x80 pixels, to be used for quantitative scientific measurements. The benefits of using this camera include the small package size, as well as a cost of ten times less than traditional thermal cameras. Software was created to convert the qualitative image into quantitative data. Several cameras were embedded into one imaging system to demonstrate the potential of integrating multiple sensors to collect more data about the object being tested. Further work will be done to verify that the sensors produce accurate quantitative data by comparing the FLIR Lepton measurements with the measurements from a higher resolution thermal camera

Effects of Different Camera Perspectives on Preservice Teachers’ Written Reflections

Promoting meaningful reflection from teacher candidates is an ongoing challenge for many teacher preparation programs. Video-based reflection provides an opportunity for candidates to examine their own teaching more closely as they reflect on their continued growth. This study examined the role of different cameras and camera angles in the reflection process for preservice teachers implementing one-on-one reading tutoring sessions. In particular, we were interested in whether using video from head-mounted cameras as a basis for reflection activities would have an influence on the focus and type of statements used in reflections. We were also interested in the advantages and disadvantages of the different cameras from the teacher candidates’ perspectives. Results indicate that camera type did not influence the focus and type of reflective statements. In general, candidates preferred the traditional camera setup, but the head-mounted camera did offer some advantages. Implications for practice and future research are discussed

Random on-board pixel sampling (ROPS) X-ray Camera

Recent advances in compressed sensing theory and algorithms offer new possibilities for high-speed X-ray camera design. In many CMOS cameras, each pixel has an independent on-board circuit that includes an amplifier, noise rejection, signal shaper, an analog-to-digital converter (ADC), and optional in-pixel storage. When X-ray images are sparse, i.e., when one of the following cases is true: (a.) The number of pixels with true X-ray hits is much smaller than the total number of pixels; (b.) The X-ray information is redundant; or (c.) Some prior knowledge about the X-ray images exists, sparse sampling may be allowed. Here we first illustrate the feasibility of random on-board pixel sampling (ROPS) using an existing set of X-ray images, followed by a discussion about signal to noise as a function of pixel size. Next, we describe a possible circuit architecture to achieve random pixel access and in-pixel storage. The combination of a multilayer architecture, sparse on-chip sampling, and computational image techniques, is expected to facilitate the development and applications of high-speed X-ray camera technology.Comment: 9 pages, 6 figures, Presented in 19th iWoRI

Gesture Recognition and Classification using Intelligent Systems

Gesture Recognition is defined as non-verbal human motions used as a method of communication in HCI interfaces. In a virtual reality system, gestures can be used to navigate, control, or interact with a computer. Having a person make gestures formed in specific ways to be detected by a device, like a camera, is the foundation of gesture recognition. Finger tracking is an interesting principle which deals with three primary parts of computer vision: segmentation of the finger, detection of finger parts, and tracking of the finger. Fingers are most commonly used in varying gesture recognition systems. Finger gestures can be detected using any type of camera; keeping in mind that different cameras will yield different resolution qualities. 2-dimensional cameras exhibit the ability to detect most finger motions in a constant surface called 2-D. While the image processes, the system prepares to receive the whole image so that it may be tracked using image processing tools. Artificial intelligence releases many classifiers, each one with the ability to classify data, that rely on its configuration and capabilities. In this work, the aim is to develop a system for finger motion acquisition in 2-D using feature extraction algorithms such as Wavelets transform (WL) and Empirical Mode Decomposition (EMD) plus Artificial Neural Network (ANN) classifier